1. Field of the Invention
The present invention relates to a lever type connector in which male and female connector housings can be connected or disconnected by rotating a lever with only a small operating force.
2. Description of the Related Art
Conventionally, for a connector which requires a large connecting force such as a multi-terminal connector, a lever type connector having a lever for assisting the connecting force has been utilized.
In the lever type connector, a lever having a cam groove on one connector housing is rotatably provided, and a cam pin to be guided by the cam groove is provided on another connector housing. The cam pin is inserted into an entry gate of the cam groove at an initial stage of connecting both connector housings where a lever is positioned at a start position. Next, the cam pin is guided into the can groove by rotating the lever, and then the both housings are firmly connected with a small operating force of the lever by utilizing the principle of leverage.
FIG. 1 to FIG. 4 show one embodiment of a conventional lever type connector described in Japanese Patent Application Laid Open No. 2004-241157. FIG. 1 shows a state before a cam pin 955 is inserted into a cam groove 940. FIG. 2 shows an initial stage of connecting in which the cam pin 955 is inserted into the cam groove 940. FIG. 3 shows an initial stage of rotating a lever 930. FIG. 4 shows a final stage of connecting in which the lever 930 is rotated to an end position.
This lever type connector has a pair of male and female connector housings 910 and 950 to be connected with each other. In each terminal cavity of the connector housings 910 and 950, terminals (not shown in figures) are accommodated. The arch-shaped lever 930 for connecting operation is attached to the connector housing 910 at outer side surface of one connector housing. An axial hole 932 and the cam groove 940 are formed on each base end of the lever 930. A knob 949 is formed on a center of the lever 930.
Each of the cam grooves 940 extends in a prescribed angle range around the axial hole 932 (center of the angle). A distance from the axial hole 932 to the cam groove 940 decreases gradually from an entry gate 941 towards an opposite end. A pin 912, to which the axial hole 932 is rotatably coupled, is provided on each side of the connector housing 910. The lever 930 is rotatably attached by coupling the pins 912 with the axial holes 932 respectively. As a result, the lever 930 will be rotated within a prescribed angle range around the pin 912 (center of the rotation) between start and end positions.
The cam pin 955 to be guided by the cam groove 940 of the lever 930 is provided on each side of the connector housing 950. When a pair of the connector housings 910 and 950 is to be connected, the cam pin 955 is positioned near the entry gate 941 of the cam groove 940 of the lever 930 positioned at the start position.
A pair of tabs 912a for preventing the lever 930 from uncoupling is provided on a tip end of each of the pin 912. The pair of tabs 912a is extended in mutually opposite directions. A pair of notches 932a corresponding to the pair of tabs 912a described above is provided with each of the axial hole 932. When the lever 930 is coupled with the connector housing 910, the pins 912 are inserted into the axial hole 932 after aligning the positions of the notches 932a and the tabs 912a. As a result, the lever 930 is attached to the connector housing 910. When the lever 930 is rotated from this attaching position, the positions of the tabs 912a and the notches 932a will become unmatched so that the lever 930 would not uncouple from the pins 912. In other words, uncoupling of the lever 930 would be prevented even when an external force applies to the lever 930.
When the above-described connector (the pair of the housings 910, 950) is to be connected, as shown in FIG. 1, the lever 930 is positioned at the start position and the pair of the connector housings 910, 950 is set face to face. Next, as shown in FIG. 2, the connector housings 910, 950 are connected loosely. At this point, the respective cam pin 955 is inserted into the entry gate 941 of the respective cam groove 940. And then, as shown in FIG. 3, the lever 930 is rotated toward the end position by grabbing the knob 949. The respective cam pin 955 is entered into the cam groove 940 from the entry gate 940, and then guided along the cam groove 940. The connector housings 910, 950 are connected by the cam structure between the cam groove 940 and the cam pin 955.
While the lever 930 is rotated, a circumferential edge of the respective axial hole 932 of the lever 930 is held by the respective tabs 912a, so that the lever 930 is held without uncoupling. As shown in FIG. 4, the connector housings 910, 950 are completely connected and the male and female terminals inside the cavities are also connected when the lever 930 has been rotated to the end position. On the contrary, the lever 930 is rotated in an opposite direction when the both connector housings 910, 950 are to be disconnected. The both connector housings 910, 950 will be disconnected by the principle of leverage applied between the cam groove 940 and the cam pin 955.
In the above-described lever type connector, the attaching position of the lever 930 is located within an ordinary rotation range of the lever 930 at connecting the connector. In other words, the start position and the attaching position of the lever 930 are coincident. For this reason, there has been a possibility for the lever 930 to uncouple when a lateral load or the like is applied during an operation of the lever 930. The connector could not be connected firmly with a small operating force if the lever 930 uncoupled.